"The Sopranos" aired on HBO from 1999 to 2007, and for most of those years, actress Jamie-Lynn Sigler (Meadow Soprano) was secretly living with multiple sclerosis.

Jamie-Lynn, now 34, told People she was diagnosed at age 20. She didn't mention it publicly because "I wasn't ready until now." She said she was symptom-free for a long time, but in the past decade her MS has "reared its ugly head."

"I can't walk for a long period of time without resting. I cannot run. No superhero roles for me. Stairs? I can do them but they're not the easiest. When I walk, I have to think about every single step, which is annoying and frustrating."

According to the National Multiple Sclerosis Society, MS "is an unpredictable, often disabling disease of the central nervous system that disrupts the flow of information within the brain, and between the brain and body."

The Art of Elysium Presents Their 9th Annual Heaven by Visionaries Vivienne Westwood & Andreas Kronthaler - Red CarpetJamie-Lynn said working after "The Sopranos" entailed trying to cover up her illness. "Sometimes all I needed was like five or 10 minutes to sit and recharge but I wouldn't ask, because I didn't want them to be suspicious."

She told People she has tried multiple MS medications, including injections and infusions, and she now takes Tecfidera twice a day, saying that has kept her symptoms stable for the past six years. Things are "manageable now," Jamie-Lynn said. "It takes a fighting attitude to deal with all this. This disease can absolutely take over your life if you let it."

The new issue of People has more on the actress's diagnosis, plus photos from her recent wedding. Best of luck to her as she continues to manage her MS.

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